I'm actually not sure how effective the Holy Instruments would be; in canon it's mentioned that holy symbols like crucifixes are pretty much useless against her (one of her spellcards is pretty much SUDDENLY THERE ARE THOUSANDS OF CROSSES COMING AT YOU WHAT DO).
Though I think since they're weapons they'd have more of an effect; FOR THE SAKE OF PLOT let's say they do. Actually, since they're solar-powered rather than Jesus-powered I think they'd get past her damage resistance and make it harder to regenerate from.
As for Flandre's weapons, she will be bringing Laevateinn with her and will probably be staying the fuck back after she gets smacked around with the glaive and/or the rosary. It's flaming sword form would do a lot of damage, but it'd have to get past the reflector, I'd think. Flandre can't swing it around that fast.
no subject
Though I think since they're weapons they'd have more of an effect; FOR THE SAKE OF PLOT let's say they do. Actually, since they're solar-powered rather than Jesus-powered I think they'd get past her damage resistance and make it harder to regenerate from.
As for Flandre's weapons, she will be bringing Laevateinn with her and will probably be staying the fuck back after she gets smacked around with the glaive and/or the rosary. It's flaming sword form would do a lot of damage, but it'd have to get past the reflector, I'd think. Flandre can't swing it around that fast.